Watercraft which can be propelled by human power

ABSTRACT

The watercraft includes: an open rigid frame having a concavity, two rigid oblong floats ( 11, 12 ) respectively fastened at the two ends of the frame, extending transversely with respect to the frame, on either side thereof, so as to offer a user a grip for his hands, and seat element ( 7 ) serving to support a user positioned astride. The frame is tubular and provided in its lower part with at least one water access orifice ( 8, 9, 10 ) and in its upper part with at least one vent (E 1 , E 2 ) enabling the frame to fill at least partially with water and act as a ballast.

The present invention concerns a watercraft which can be propelled by human power and which is applicable to recreation, athletic training or even rehabilitation, both for able-bodied and handicapped persons.

It more particularly has for object a watercraft of the type described in application WO 2006/114524 and which comprises:

-   -   an open rigid frame having a concavity, for example U-, lyre- or         omega-shaped,     -   two rigid oblong floats, respectively fastened at the two ends         of the frame, these two floats extending transversely with         respect to said frame, on either side thereof, so as to offer a         user a grip for his hands,     -   seat means which can consist of a covering in a relatively         flexible material which at least partially covers the bottom of         the concavity of the frame (bottom of the U), serving to support         at least one user positioned astride in this concavity and         pressing his hands on one of the floats so as to be able to         freely move his legs in the water whereby moving with said         watercraft.

In the aforementioned patent application, the frame usually has a trough-shaped portion serving to house an inflatable element, such that the submerged portion of the craft globally has a lower density than that of the water. Because of this, when the user is seated astride on the bottom of this frame and floats in the water, the center of gravity of the floating assembly whereof the submerged portion is subjected to the buoyancy and raised in relation to the surface of the water, which reduces the stability of this assembly. Due to the reduced stability, the movements made by the user risk causing tilting thereof. This problem arises very sharply in the case where the craft is used for paraplegics and during rehabilitation sessions during which the patient must perform exercises which are very difficult to master.

Of course, the use of a ballast at the lower portion of the frame can constitute one solution to this problem. However, this solution makes the craft considerably heavier and therefore makes it much more difficult to manipulate out of the water.

The invention therefore first aims to eliminate these drawbacks.

To this end, it proposes a watercraft of the aforementioned type provided with a tubular frame comprising, in its lower portion, at least one water access orifice and, in its upper portion, at least one air passage orifice or vent, provided such that when the craft is in the water, the frame fills at least partially with water, the water contained inside the frame then acting as a ballast.

The vent may potentially be provided with sealing means so as to allow the user to control the quantity of water inside the frame, in particular with the aim of adjusting the center of gravity of the floating assembly in relation to the center of rotation of the frame.

This solution is useful in particular in the case where the frame is equipped with means for propelling the craft exploiting the rotational movements of the frame.

Advantageously, these propulsion means could consist of a flexible flipper or fin fastened on one of the two posts of the frame, essentially mid-height thereon and extending toward the outside of the frame, in a plane passing through an axis of rotation of the frame, in the vicinity of said cable.

According to other alternative embodiments of the invention:

-   -   The craft may comprise at least one blade rotatingly mounted on         the rear portion of the frame (for example under the rear         float), as well as at least one lever rotatingly mounted on the         front portion of the frame, for example under the second float,         transmission means being provided in order to obtain a flapping         movement of the flipper under the effect of the alternating         tilting of the actuating lever.     -   The craft may comprise two levers rotatingly mounted on the         front portion of the frame and transmission means causing the         flapping movements of the flipper under the effect of the         actuation of the two levers.     -   The craft may comprise two flippers and two levers, respectively         mounted on the rear and front portions of the frame, each lever         being coupled to a corresponding flipper by independent         transmission means.     -   The aforementioned flippers and the aforementioned levers are         mounted rotatingly on a rigid structure housed inside the         tubular frame and engaging between the two halves of the shell         of said frame so as to obtain disconnectable fastening.     -   The aforementioned transmission means may comprise disengageable         connections making it possible to adjust the travel of the         levers in relation to the travel of the flippers.     -   The frame of the craft may be provided with a support foot         and/or means for running along the ground.

Embodiments of the invention will be described below, as non-limiting examples, in reference to the appended drawings in which:

FIGS. 1 to 3 are diagrammatic cross-sections illustrating the operating principle of the watercraft, in the normal float position (FIG. 1), in its position rotated forward (FIG. 2) and in its position rotated backward (FIG. 3);

FIG. 4 is an exploded perspective view of the craft illustrated in FIGS. 1 to 3;

FIG. 5 is a top view of the craft illustrated in FIG. 4 in its assembled position;

FIGS. 6 and 7 are side (FIG. 6) and top (FIG. 7) views, respectively, of an alternative embodiment of the craft according to the invention provided with flippers;

FIG. 8 is a perspective view of the craft illustrated in FIGS. 5 and 6;

FIG. 9 is a diagrammatic cross-section of the frame of the engine illustrated in FIGS. 6 to 8, at the level of the drive shafts;

FIG. 10 is a diagrammatic transverse cross-section of the frame of the craft illustrated in FIGS. 6 to 9 at the level of a return pulley assembly;

FIG. 11 is a diagrammatic illustration of the drive mechanism of the flippers of the craft illustrated in FIGS. 6 to 10.

In this example, the watercraft comprises a rigid tubular frame having an inverted Ω shape which comprises an essentially circular open central portion 1 in its upper portion and the two ends of which are bent and extended by respective wings 2, 3 which extend outward coaxially in relation to each other and which each support a mortise assembly profile 4, 5.

These assembly profiles 4, 5 each comprise a vent E₁, E₂ enabling connection of the interior volume of the tubular frame with the outside. These vents can be closed by a stopper O₁, O₂, for example of the needle valve type. This tubular frame may be made in a light material such as a plastic.

The central portion 1 of the tubular frame comprises, in its lower portion 6, a zone covered by a flexible lining 7 in the form of a semi-cylindrical shell, for example in closed-cell expanded plastic material. This lining serves as a seat for a user 8 positioned astride on the seat.

The zone of the lower portion 6 of the frame which is opposite the lining 7 is provided with three water passage orifices 8, 9, 10. These orifices 8, 9, 10 are designed to allow the tubular frame to fill with water when it is at least partially submerged. This filling, which takes place by expelling the air content via the vents E₁, E₂ makes it possible to obtain “ballasting” of the watercraft. The water level inside the frame can potentially be adjusted as desired by the user using the stoppers O₁, O₂ provided with the vents.

On the assembly profiles 4, 5 engage the two respective oblong floats 11, 12 thanks to assembly profiles 13, 14 (pins) with shapes complementary to those of the assembly profiles 4, 5 (mortises). These floats 11, 12 assume the form of curved rolls essentially similar to handlebars.

Each of the floats 11, 12 is provided with two handles 15, 16 respectively arranged on either side of its assembly profile 13, 14. Each handle 15, 16 is made up of a ring bent at a right angle which extends into the concavity of the circular form of the float 11, 12 between one of its ends and its central region.

Likewise, two additional handles 17, 18 are provided, each formed by a ring bent into a C shape whereof the ends are fastened on the convex surface of the float 11, 12 opposite a handle 15, 16.

In this example, each of the floats 11, 12 is also provided at both of its ends with two respective protuberances 19, 20 each provided with a passage orifice, for example a tie.

Moreover, the frame comprises in its central region, essentially at half-height, two radial connecting pins 21, 22 on each of which a flat, elastically deformable fin 23 can engage and fasten, said fin extending in a plane (in principle horizontal) perpendicular to the general plane of the frame. In this example, the fin 23 has a cardioid shape.

The assembly of this fin 23 on the frame is done using a fork joint 24 in which one of the two pins 21, 22 engages. The two wings of the fork joint as well as the pin are each passed through by two bores arranged such that in the assembled position of the pin 21, 22 in the fork joint 24, one obtains two through passages in which two fastening pins potentially integral with each other at one of their ends can engage.

The craft described above operates as follows:

When it is put in the water, the frame fills at least partially with water which penetrates through the orifices and expels a corresponding volume of air via the vents until it floats on the water thanks to the floats 11, 12, the central portion 1 of the frame which is submerged then acts as a boat keel.

Once filled with water, the craft has optimum stability and becomes practically uncapsizable.

The user then straddles the frame and sits astride on the lining 7 in the position illustrated in FIG. 1, holding the handles 15, 16 of the float 12 situated in the front.

From this position, the user can choose to use one of two propulsion methods.

The first propulsion method consists of leaning forward in relation to the horizontal axis and pedaling like a cyclist or kicking the legs like a swimmer. In this case, the fin 23 is not used.

The second propulsion method consists of causing, by alternatingly leaning forward and backward and exerting stress on the handles 15, 16, rotation of the frame in its plane around its axis of rotation R.

FIG. 2 illustrates a position of the user leaning backward. During the rotation of the frame making it possible to arrive at this incline, the fin deforms elastically upward while accumulating the potential energy which it then releases in returning to its initial position while exerting a forward propulsive stress on the craft.

When the user leans forward under the effect of the water resistance, the fin 23 deforms downward to the position illustrated in FIG. 3, then returns to its initial position while exerting a forward propulsive stress on the craft.

It clearly appears that this second propulsion method only uses the legs very slightly, or not at all, such that it is particularly suitable for paraplegic persons.

Of course, in the event the vents E₁, E₂ are provided with stoppers, the user will be able to adjust the water level inside the frame so as to bring the center of gravity of the user/craft assembly as close as possible to the center of rotation of the craft.

Furthermore, the rotational movement of the frame is amplified thanks to a thrust/traction action on the handles 15, 16 by the user's hands, alternatively upward and downward. This propulsion method therefore makes it possible to work the user's arms without, however, excluding working the legs (which can be adapted to the user's handicap).

In the example illustrated in FIGS. 6 to 11, the tubular frame 30 of the watercraft 31 is made in two half-shells 32, 33 with a straight C-shaped section, assembled together at their lateral edges, using screws 34 passing through counter bored holes whereof the chambers are designed to receive the screw heads 34 and/or the nuts.

The tubular frame 30 engages by its ends in cavities provided in the floats 35, 36, locking being ensured by a locking means such as one or several screws, for example.

In a median horizontal plane, these floats 35, 36 have a curved shape 37 on one side which extends toward the outside of the frame 30 and, on the side opposite the preceding side, an indented shape 38. This indented shape 38 comprises two indentations 39, 40 respectively situated on either side of a central portion 41 comprising the cavity 42 in which one end of the tubular frame 30 engages (FIG. 7).

In a vertical plane perpendicular to the longitudinal median plane of symmetry of the frame 30, each float fits into a slightly flattened oval shape (FIG. 6). In this example, the rounded form 37 has two indentations 39′, 40′ situated in the extension of the indentations 39, 40.

The two floats 35, 36 have identical shapes and each also comprise vertically centered through recesses 41, 42, 43, 44 which each define, with the edge of the float, a grip handle 41′, 42′ 43′ 44′. Like the embodiment previously described, the central portion of the tubular frame comprises an upper zone covered by a flexible lining 45 consisting of a shell having, in a transverse vertical plan, an inverted U shape.

Opposite this lining 45, the tubular frame has at least one water passage orifice 46 designed to allow filling of the frame when the latter part is at least partially submerged.

Below the float 36, which is meant to be the front float, the tubular frame 30 comprises two coaxial through bores 47, 48 centered perpendicular to the longitudinal plane of symmetry of the frame 30. These two bores 47, 48 are designed to ensure the passage of two respective coaxial drive shafts 49, 50 (FIG. 9).

These two drive shafts 49, 50 are rotatingly mounted on a rigid structure 51 housed inside the frame 30.

The ends of these two shafts 49, 50 which come out of the frame 30 are integral with two respective bent actuating levers 52, 53.

These two levers 52, 53 are designed to be actuated by hand by a user using a tilting movement alternating between a front position in which they each engage in the bottom of a corresponding indentation 39, 40 of the float 36 to a rear position in which they are outside the indentations 39, 40.

The bent form of the levers 52, 53 is designed to shift the ends of the levers, which act as handles for the user, as far forward as possible.

One thereby obtains an ergonomic arrangement allowing the user to best exploit the strength of his arms.

In this example, the end of each handling lever 52, 53 is provided with a spherical knob 54, 55, to act as handholds for the hands.

Furthermore, under the (rear) float 35 situated opposite the front float 36, but at a lower height than that of the bores 47, 48 (at approximately ⅔ of the height of the frame 30), the frame 30 comprises two coaxial bores centered parallel to the bores 47, 48, which are designed to ensure the passage of two respective coaxial drive shafts 56, 57 according to an assembly similar to that shown in FIG. 9.

These two drive shafts 56, 57 are rotatingly mounted on the rigid structure 51 housed inside the frame 30.

Fixed on these two drive shafts are two respective flippers 58, 59 having shapes similar to those of the flippers which are usually used by swimmers, but without housings for the feet.

In this example, the fastening of the flippers on the drive shafts 56, 57 is done by screwing, via fastening means allowing adjustment of the orientation of the flippers.

The two drive shafts 49, 50-56, 57 situated on a same side of the longitudinal plane of symmetry of the frame 30 are coupled to each other by a transmission mechanism of the traditional type. In this example, this mechanism involves the use of a transmission by cables and return pulleys.

As illustrated in FIG. 11, the rigid structure 51 comprises a beam P having a bent shape corresponding to the bent shape of the frame 30, here an essentially trapezoidal shape open at the large base.

This beam P supports, at each of the pairs of bores 47, 48, a transverse shaft 60 which extends coaxially to the bore pairs 47, 48, on either side of the beam P. The ends of this shaft 60 which exceed on either side of the beam P constitute journals on which two respective tubular drive shafts 49, 50 engage each supporting, inside the frame 30, a double drum T1, T2-T3, T4 on which the ends of two cables C1, C2-C1′, C2′ fasten and wind.

The tubular drive shafts 49, 50-56, 57 are made integral at their ends which come out of the frame 30 with the actuating levers 52, 53 and the flippers 58, 59, respectively, via a cylindrical hub 61, 62-61′, 62′, for example made in a plastic material.

Inside the frame 30, the two pairs of cables C1, C′-C2, C′2 (one pair per side of the beam P) are guided by two pairs of wheel pairs PC1, PC2 arranged respectively at the angular region of the trapezoidal shape of the beam P. FIG. 10 shows a pair of wheel pairs PC1.

The wheels 65, 66-67, 68 of each of the pairs of wheel pairs PC1, PC2 are mounted pivoting around a transverse shaft 70 passing through the beam P and extending from both sides thereof to form two journals.

Thanks to these arrangements, the tilting of a lever 52, 53 in a direction causes the rotation of a first corresponding drum T1, T2 and as a result the winding of one of the cables C1 of this drum T1, T2 and the unwinding of the second cable C2 from this drum T1, T2.

The winding of the first cable C1 causes, on the second drum T3, T4 connected to the flipper 58, 59, situated on the same side, an unwinding of this cable C1 with a rotational driving of the second drum T3, T4 and of the corresponding flipper 58, 59. The second cable C2 then undergoes winding on the second drum T3, T4 and unwinding on the first drum. The backward tilting of the lever 52, 53 will cause an action opposite the preceding one with backward rotation of the flipper 58, 59.

Upon each rotation of the flipper 58, 59, the craft will be propelled forward.

A similar process is done on the other side of the beam P upon tilting of the second lever 52, 53, with the understanding that the two kinematic mechanisms for driving the flippers 58, 59 are independent.

In this example, the flippers can be directly actuated by the user using straight levers 70, 71 equipped with handles directly fastened on the hub 61′, 62′ used for fastening of the flippers 58, 59.

Of course, the invention is not limited to the embodiments previously described.

Thus, for example, the beam P may at least partially assume the shape of a plate provided with fastening means engaged between the two half-shells 32, 33, the assembly of this plate and its equipment (cables/shafts/drums/wheels . . . ) constituting a cassette easy to assemble or disassemble whether to facilitate craft maintenance or even to modify the configuration of the craft.

Likewise, it is possible to provide a removable seat by replacing the lining 45. This seat may be specially designed for handicapped persons.

Moreover, the frame 30 may be equipped with a support foot and/or running means to ensure the stability of the craft on the ground and/or its possible movement on the ground. 

1. A watercraft which can be propelled by human power comprising: a rigid frame (30) having a shape defining a concavity, two rigid oblong floats (11, 12) respectively fastened to the two ends of the frame, these two floats (11, 12) extending transversely in relation to said frame, on either side thereof, so as to offer a user a grip for his hands, and seat means (7) serving to support a user positioned astride in said concavity, characterized in that said frame is tubular and comprises, in its lower portion, at least one water access orifice (8, 9, 10) and in its upper portion, at least one air passage orifice or vent (E₁, E₂) provided such that, when the craft is in the water, the frame fills at least partially with water and the water contained inside the frame acts as a ballast.
 2. The watercraft according to claim 1, characterized in that the aforementioned vent (E₁, E₂) is provided with sealing means (O₁, O₂) so as to allow the user to control the amount of water inside the frame.
 3. The watercraft according to claim 1, characterized in that the frame is equipped with propulsion means using the rotational movements of the frame.
 4. The watercraft according to claim 3, characterized in that the aforementioned propulsion means consist of a flipper (23) or flexible fin, elastically deformable, fastened on one of the posts of the frame, essentially at mid-height thereof, this flipper (23) extending toward the outside of the frame.
 5. The watercraft according to claim 4, characterized in that the aforementioned flipper (23) extends in a plane passing through the axis of rotation (R) of the frame or in the vicinity of said axis.
 6. The watercraft according to claim 4, characterized in that the aforementioned flipper (23) has a cardioid shape.
 7. The watercraft according to claim 4, characterized in that the posts of the aforementioned frame are provided with means allowing a disconnectable assembly of said flipper (23).
 8. The watercraft according to claim 1, characterized in that the central portion of said frame comprises a zone covered with a flexible lining (7) in the form of a semi-cylindrical shell serving as a seat.
 9. The watercraft according to claim 8, characterized in that said lining (7) is made of a closed-cell expanded plastic material.
 10. The watercraft according to claim 1, characterized in that said frame is made in a light material such as a plastic.
 11. The watercraft according to claim 1, characterized in that it comprises at least one flipper rotatingly mounted on the rear portion of the frame (30) as well as at least one actuating lever (52, 53) rotatingly mounted on the front portion of the frame (30) as well as transmission means making it possible to cause a flapping movement of the flipper (58, 59) under the effect of an alternating tilting movement of the drive lever (52, 53).
 12. The watercraft according to claim 11, characterized in that it comprises two levers (52, 53) articulated on the front portion of the frame (30), and in that the flapping movements of the flipper (58, 59) are caused by the alternating tilting of the two levers (52, 53).
 13. The watercraft according to claim 11, characterized in that it comprises two flippers (58, 59) rotatingly mounted on the rear portion of the frame (30) as well as two actuating levers (52, 53) articulated under the front portion of said frame (30), each lever (52, 53) being coupled to a corresponding flipper (58, 59) by an independent transmission means.
 14. The watercraft according to claim 11, characterized in that said transmission means are of the cable/drum and return wheel type.
 15. The watercraft according to claim 11, characterized in that said flippers (58, 59) and said levers (52, 53) are rotatingly mounted on a rigid structure (51) housed inside the frame (30).
 16. The watercraft according to claim 11, characterized in that it comprises an additional actuating lever (70, 71) integral with said flipper or said flippers (58, 59).
 17. The watercraft according to claim 15, characterized in that said rigid structure (51) also supports said transmission means and is fastened on the frame using disconnectable fastening means so as to be able to assemble and disassemble said rigid structure (51) with its equipment like a cassette.
 18. The watercraft according to claim 11, characterized in that the tubular frame (30) is made in two half-shells (32, 33) which can be assembled together at their lateral edges, and in that said rigid structure (51) engages between said lateral edges for its fastening on the frame.
 19. The watercraft according to claim 11, characterized in that said actuating levers (52, 53) have a bent shape and engage in indentations (39, 40) provided in said floats.
 20. The watercraft according to claim 11, characterized in that the transmission means comprise a disengageable connection making it possible to adjust the travel of the lever(s) (52, 53) in relation to the travel of the flipper(s) (58, 59).
 21. The watercraft according to claim 1, characterized in that the frame (30) is provided with a foldable support foot and/or rolling means to ensure the stability of the craft on the ground and/or of any movement thereof on the ground.
 22. The watercraft according to claim 11, characterized in that the ends of the frame (30) engage in cavities provided in the floats (35, 36). 